package com.example.hcd.tool;

import com.example.hcd.R;
import com.example.hcd.functionactivity.ShowPictureList;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.widget.ImageView;

public class TouchImageView extends ImageView {  
  
    float x_down = 0;  
    float y_down = 0;  
    PointF start = new PointF();  
    PointF mid = new PointF();  
    float oldDist = 1f;  
    float oldRotation = 0;  
    Matrix matrix = new Matrix();  
    Matrix matrix1 = new Matrix();  
    Matrix savedMatrix = new Matrix();  
  
    private static final int NONE = 0;  
    private static final int DRAG = 1;  
    private static final int ZOOM = 2;  
    int mode = NONE;  
  
    boolean matrixCheck = false;  
  
    int widthScreen;  
    int heightScreen;  
  
    Bitmap gintama;  
  
    public TouchImageView(ShowPictureList activity) {  
        super(activity);  
        gintama = BitmapFactory.decodeResource(getResources(), R.drawable.image);  
  
        DisplayMetrics dm = new DisplayMetrics();
        activity.getWindowManager().getDefaultDisplay().getMetrics(dm);  
        widthScreen = dm.widthPixels;  
        heightScreen = dm.heightPixels;  
  
        matrix = new Matrix();  
    }  
  
    protected void onDraw(Canvas canvas) {  
        canvas.save();  
        canvas.drawBitmap(gintama, matrix, null);  
        canvas.restore();  
    }
    
    public void setImageBitmap(Bitmap bitmap) {
    	gintama = bitmap;
		invalidate();
	}
  
    public boolean onTouchEvent(MotionEvent event) {  
        switch (event.getAction() & MotionEvent.ACTION_MASK) {  
        case MotionEvent.ACTION_DOWN:  
            mode = DRAG;  
            x_down = event.getX();  
            y_down = event.getY();  
            savedMatrix.set(matrix);  
            break;  
        case MotionEvent.ACTION_POINTER_DOWN:  
            mode = ZOOM;  
            oldDist = spacing(event);  
            oldRotation = rotation(event);  
            savedMatrix.set(matrix);  
            midPoint(mid, event);  
            break;  
        case MotionEvent.ACTION_MOVE:  
            if (mode == ZOOM) {  
                matrix1.set(savedMatrix);  
                float rotation = rotation(event) - oldRotation;  
                float newDist = spacing(event);  
                float scale = newDist / oldDist;  
                matrix1.postScale(scale, scale, mid.x, mid.y);// 縮放  
                matrix1.postRotate(rotation, mid.x, mid.y);// 旋轉  
                matrixCheck = matrixCheck();  
                if (matrixCheck == false) {  
                    matrix.set(matrix1);  
                    invalidate();  
                }  
            } else if (mode == DRAG) {  
                matrix1.set(savedMatrix);  
                matrix1.postTranslate(event.getX() - x_down, event.getY()  
                        - y_down);// 平移  
                matrixCheck = matrixCheck();  
                matrixCheck = matrixCheck();  
                if (matrixCheck == false) {  
                    matrix.set(matrix1);  
                    invalidate();  
                }  
            }  
            break;  
        case MotionEvent.ACTION_UP:  
        case MotionEvent.ACTION_POINTER_UP:  
            mode = NONE;  
            break;  
        }  
        return true;  
    }  
  
    private boolean matrixCheck() {  
        float[] f = new float[9];  
        matrix1.getValues(f);  
        // 图片4个顶点的坐标  
        float x1 = f[0] * 0 + f[1] * 0 + f[2];  
        float y1 = f[3] * 0 + f[4] * 0 + f[5];  
        float x2 = f[0] * gintama.getWidth() + f[1] * 0 + f[2];  
        float y2 = f[3] * gintama.getWidth() + f[4] * 0 + f[5];  
        float x3 = f[0] * 0 + f[1] * gintama.getHeight() + f[2];  
        float y3 = f[3] * 0 + f[4] * gintama.getHeight() + f[5];  
        float x4 = f[0] * gintama.getWidth() + f[1] * gintama.getHeight() + f[2];  
        float y4 = f[3] * gintama.getWidth() + f[4] * gintama.getHeight() + f[5];  
        // 图片现宽度  
        double width = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));  
        // 缩放比率判断  
        if (width < widthScreen / 3 || width > widthScreen * 3) {  
            return true;  
        }  
        // 出界判断  
        if ((x1 < widthScreen / 3 && x2 < widthScreen / 3  
                && x3 < widthScreen / 3 && x4 < widthScreen / 3)  
                || (x1 > widthScreen * 2 / 3 && x2 > widthScreen * 2 / 3  
                        && x3 > widthScreen * 2 / 3 && x4 > widthScreen * 2 / 3)  
                || (y1 < heightScreen / 3 && y2 < heightScreen / 3  
                        && y3 < heightScreen / 3 && y4 < heightScreen / 3)  
                || (y1 > heightScreen * 2 / 3 && y2 > heightScreen * 2 / 3  
                        && y3 > heightScreen * 2 / 3 && y4 > heightScreen * 2 / 3)) {  
            return true;  
        }  
        return false;  
    }  
  
    // 触碰两点间距离  
    private float spacing(MotionEvent event) {  
        float x = event.getX(0) - event.getX(1);  
        float y = event.getY(0) - event.getY(1);  
        return (float)Math.sqrt(x * x + y * y);
    }  
      
    // 取手势中心点  
    private void midPoint(PointF point, MotionEvent event) {  
        float x = event.getX(0) + event.getX(1);  
        float y = event.getY(0) + event.getY(1);  
        point.set(x / 2, y / 2);  
    }  
  
    // 取旋转角度  
    private float rotation(MotionEvent event) {  
        double delta_x = (event.getX(0) - event.getX(1));  
        double delta_y = (event.getY(0) - event.getY(1));  
        double radians = Math.atan2(delta_y, delta_x);  
        return (float) Math.toDegrees(radians);  
    }  
  
    // 将移动，缩放以及旋转后的图层保存为新图片  
    // 本例中沒有用到該方法，需要保存圖片的可以參考  
    public Bitmap CreatNewPhoto() {  
        Bitmap bitmap = Bitmap.createBitmap(widthScreen, heightScreen,  
                Config.ARGB_8888); // 背景图片  
        Canvas canvas = new Canvas(bitmap); // 新建画布  
        canvas.drawBitmap(gintama, matrix, null); // 画图片  
        canvas.save(Canvas.ALL_SAVE_FLAG); // 保存画布  
        canvas.restore();  
        return bitmap;  
    } 

}
